Using tissue samples from mummified bodies, they are tracing the development of schistasomiasis, a chronic debilitating disease.

The disease, which has minor symptoms in the short term but can cause death after repeated exposure, has been detected in mummies from 2,800BC.

It is caused by a parasite called a schistasome.

Dr Rosalie David, keeper of Egyptology at Manchester University, described the project in a public lecture at Newcastle University.

Modern techniques

Her multidisciplinary department, made up of archaeologists, scientists and doctors, applies modern forensic and clinical techniques to examine ancient tissue and establish what diseases affected people in the distant past.

They have found that many familiar diseases affected the ancient Egyptians - obesity, osteoarthritis, slipped discs, blocked arteries and pleurisy.

But the researchers particularly want to track the progress of schistasomiasis.

The disease is estimated to affect 200-300 million people in 79 countries. In some Egyptian villages it can affect as much as 80% of the population.

It is caused by the schistasome fluke worm, which lives in the Nile. It provokes symptoms in humans when it lays its eggs under the skin.

The disease can have a major impact on an agricultural workforce as well as a nation's economy.

The researchers hope they can work out how the disease has been so successful at disrupting human life by studying the progression of the disease and its cause over a period of 5,000 years.

International project

The Manchester Mummy Project is working with the Ministry of Health in Egypt and Dr George Contis of the Medical Service Corporation International in the US on the research.

Modern analysis is applied to ancient tissue

They are using polymerase chain reaction (PCR) techniques, which analyse DNA, to see if there is any difference between the ancient and the modern version of the worm.

Dr David said: "It's a very clever, adaptive being and because it's so successful we want to find out why.

"This could enable us in the future to find some way to combat it in the modern state."

The first clues to the presence of the disease in the ancient world lie in the medical textbooks of the time, Dr David said.

The ancient Egyptians kept their medical knowledge on papyrus - ancient paper - and had three types of medical papyri.

There were handbooks for surgeons' daily use, outlines for medical lectures and students' records and a combination of lecture and case notes.

Magical medicine

Although Egyptian medicine was divided between the magical and the rational, there is no doubt it was highly sophisticated, she added.

The existing medical papyri refer to worms as "the occupier and destroyer of the body".

A disease referred to as the "rrr" is mentioned in them 50 times, and some specialists say this is a reference to schistasomiasis.

However, Dr David thinks this is unlikely, and said that confirmation of the disease's early prevalence only came when traces of it were found in mummified tissue.

Signs such as a calcified or damaged bladder indicate the disease's presence.

But finding these indicators is difficult in tissue that is millennia old.

Developing science

Dr David outlined the development of her team's scientific techniques to analyse mummified bodies at the lecture.

Ancient treasures proved popular souvenirs

She started at the beginning, in the 18th and 19th centuries when mummies became a popular souvenir.

Early tourists would return from the country with a crocodile under one arm and a mummy under the other, she said.

In the late 1700s unwrapping mummies became fashionable, and people would gather for afternoon unwrapping sessions.

Most of these were shambolic affairs, with few notes taken and the mummy being destroyed, Dr David said.

In 1825, the Leeds Literary and Philosophical Society performed a "scientifically respectable unwrapping and autopsy," she said.

This paved the way for Margaret Murray to form a multidisciplinary group dedicated to serious study and autopsies of mummies when she became keeper of Egyptology at Manchester in 1908.

Dr David said she revived the idea of such a team when she joined the university in 1972.

Their aim is to look at disease and causes of death in ancient Egypt as well as other aspects of lifestyle.

Her team performed an unwrapping in 1975, but since then they have developed a range of techniques that mean they can analyse tissue and leave the mummy intact.

Fabric softener

Using X-rays and small samples of tissue they can build a picture of the mummy's health in life.

However, mummified tissue is dry and brittle.

Before the team can run tests on it they have to rehydrate it, and they do this using, among other things, fabric softener.

But once the tissue is "refreshed" in this way, it can be tested for schistasomiasis using a simple test that makes affected tissue turn green.

Dr David hopes that the project will prove successful because it offers the team the chance to study the progress of the same disease among the same people over such a long period of time.